Multiple punch and die assembly

Abstract

A multiple punch and multiple die assembly has a workpiece protector which is a punch lifter that is operatively associated with each punch for supporting each of the punches in an inactive position as an active punch is moved by the ram to the active, i.e. operating position to thereby eliminate scoring or marking of the sheet material or other workpiece that is being punched. To eliminate the need for hand tools and hand assembly or disassembly, a manually moveable retainer on the punch assembly is provided that can be moved by hand between a punch-releasing and punch-retaining position for holding the punches within the multi-punch assembly during operation. To prevent stress fractures that formerly occurred in die carriers, support of each die is distributed between two different die components thereby reducing impact stress on the carrier as the ram drives the punch through the workpiece.

1. A multiple punch and die assembly adapted to be placed in a punch press having a punch ram for imparting movement to the punch assembly for carrying out a punching or forming operation comprising,
 a punch assembly having a punch guide with a plurality of selectively operable punches mounted therein for independent axial reciprocating movement in the guide such that each punch thus selected engages a workpiece when in an operating position, 
 a punch carrier for holding a plurality of the punches which are yieldably supported on the punch guide, 
 the punches being positioned to be struck selectively by the ram such that one punch is driven through the punch guide to an operating position when at least one other punch is inactive, 
 each of the punches having a resilient workpiece protector element for yieldably elevating each such punch above the punch carrier, 
 each such workpiece protector element being operatively associated with a punch to thereby support each such inactive punch at an elevation preventing each inactive punch from making a workpiece during a punching operation, 
 wherein each punch is operatively engaged by a resilient workpiece protector element so as to elevate each inactive punch above an operating position, and 
 each inactive punch is thereby supported by a workpiece protector element located when each active punch moves toward an operating position as the ram drives the active punch through the punch guide; wherein each workpiece protector element comprises at least one compression spring connected between each such punch and a part of the punch guide located beneath a lower end of each workpiece compression spring, and wherein each workpiece protector element provides resilient support for one such punch while maintaining an upper end thereof suspended above an upper surface of the punch carrier. 
 
     
     
       2. The apparatus of  claim 1  wherein each punch operatively engages a resilient workpiece protector element so that each punch is held above an operating position by supporting each punch that is in an inactive position, and
 each inactive punch is held by the resilient workpiece protector element to support an upper end of the punch above the punch carrier such that the path of the punch moving toward an operating position passes through the punch carrier as a ram drives the punch through the punch guide. 
 
     
     
       3. The apparatus of  claim 1  wherein
 each punch is supported by a lifter pin member located between each resilient workpiece protector element and the punch. 
 
     
     
       4. The apparatus of  claim 1  wherein each punch is supported by one of the resilient workpiece protector elements such that during operation each inactive punch is elevated sufficiently so as to not rest upon the punch carrier. 
     
     
       5. The apparatus of  claim 1  wherein the punch carrier has a plurality of openings that each hold one of the punches and each opening is located below a boss on a punch that is elevated above the opening in the punch carrier by the resilient workpiece protector element.